Download Electronic Structure of Atom

L2
Electronic Structure of Atoms
Four quantum numbers characterize the
electron :
1) principal п = 1, 2, 3, 4, ...;
2) orbital (angular) l = 0, 1, 2, ..., (п
3) magnetic m = 0, 1,...,  l;
4) spin s
- 1);
= +1/2,-1/2.
1
Electronic Structure of Atoms
The energy depends on п
The set of electrons having the same
principal quantum number п is called
a shell. Shells are subdivided into
subshells, which have different
quantum numbers l.
2
Electronic Structure of Atoms
The following notation is
convenient
Quantum
number п
Symbol
1 2 3 4 5 6 7
K L M N O P Q
3
Electronic Structure of Atoms
Inside shell, the electrons with different
angular numbers l build up subshells:
Angular
momentum,
Symbol
0 1 2 3 4 5
l
s
p d f
g h
4
Electronic Structure of Atoms
Pauli’s exclusion principle states that no
two electrons in an atom may have
same set of quantum numbers. .
In accordance with this principle in a
state characterized by three quantum
numbers п, l, and т, no more than two
electrons with opposite spins can be
found.
5
Electronic Structure of Atoms
There are: two electrons in K – shell,
eight electrons in L – shell, eighteen
electrons in М – shell, and so on.
There are: two electrons in s – subshell,
six electrons in p – subshell, ten
electrons in d – subshell and so on.
6
Electronic Structure of Atom
The electron configuration of elements
11Na
Si
14
2
2
6
1s 2s 2 p 3s
1
.
2
2
6
2
1s 2s 2 p 3s 3 p
2
7
Electronic Structure of Atom
.
The potential well
of an isolated
atom and energy
levels of
electrons
8